HEALTHCARE
LAYING THE FOUNDATIONS FOR SUCCESSFUL MODULAR BUILDINGS Declan Armour, Managing Director of Shanco Contracts, explains the importance of effective groundworks for modular buildings and how the healthcare sector can avoid unnecessary costs and delays.
T
he speed and ease of modular construction are two of its major benefits for the healthcare sector. However, the success of a modular building project relies on several elements and one of the most important is the groundworks. Difficulties with planning and inadequate site research can diminish some of the benefits of offsite construction, leading to programme delays and unexpected costs. To avoid these risks and drive efficiencies across the project, there are several factors to consider.
Early engagement An experienced groundworks contractor should be involved in a modular build project at the earliest opportunity – ideally the tender stage. This enables any potential challenges, which could affect the construction programme and costs, to be identified from the outset. To assist with this process, a groundworks contractor should be provided with
14
as much information as possible about the site and the building’s design. This means all eventualities can be considered and, if necessary, incorporated into the budget and the projected duration of the project. For example, limited site access may affect the type of plant and equipment that could be used for groundworks, which, in turn, may impact the overall construction programme. Similarly, constrained sites may present difficulties for work further down the line, limiting space for jobs, such as the building installation or cladding and roofing, as well as the crane and access equipment required to carry them out. Like most large construction projects, modular builds are likely to require alterations to the site’s entry, surrounding roads and drainage connections. These elements, including the required approvals, should also be considered during the planning stage to avoid costly delays.
Ground conditions No matter how poor the ground conditions, it should be possible to create a foundation solution that supports the modular structure. However, it is essential to investigate the site at the earliest opportunity to identify any potential problems and how these can be resolved. The type and condition of the ground will determine what foundations will be required to support the structure. For example, if the ground consists of clay, this can be problematic for water retention and drainage. This may require additional measures to be put in place to control surface water, such as the installation of attenuation tanks and SUDS designs. Some clays may also mean the ground has less load-bearing capacity, so specialist piling solutions could be required. Similarly, sandy and loose soils can present comparable challenges in terms of the stability of foundations.
A modular project for a Bolton hospital highlights the potential impact of ground conditions on projects. Working within a highly constrained site next to the main hospital building, we had to overcome several challenges to deliver the groundworks for the modular build. As ground conditions were poor, it was not possible to lay pad foundations. Instead, a reinforced concrete raft slab had to be laid under the building’s entire footprint followed by plinths for levelling. Adding to the complexity of the work, a service tunnel ran diagonally through the site under the concrete slab providing electricity as well as medical gases into the hospital. To reduce the heavy loadings over the tunnel from plant and machinery, a temporary crossing bridge was built over it for the construction phase. We worked closely with the structural engineers to create and install the bridge, and ensured the concrete foundation slab could adequately support the building over the tunnel.
